1. Field of the Invention
The present invention relates to an ink tank, a tank holder to detachably hold the ink tank, an ink jet head cartridge provided with an ink jet head mounted on the tank holder to discharge ink for recording, and an ink jet recording apparatus provided with the ink jet head cartridge.
2. Related Background Art
FIG. 25 is a perspective view which shows the general ink jet recording apparatus conventionally in use. For the ink jet recording apparatus shown in FIG. 25, the lead screw 104 and the guide shaft 105, which are arranged to be in parallel to each other, are provided for a housing. For the lead screw 104 and the guide shaft 105, a carriage 101 is installed to be able to travel in the direction parallel to the lead screw 104 and the guide shaft 105. The carriage 101 is driven to travel in parallel to the lead screw 104 which is rotated by a carriage motor (not shown).
As described later in conjunction with FIGS. 26A and 26B, the ink jet head cartridge provided with the ink jet head 102 is mounted on the carriage 101. In the vicinity of the traveling orbital plane of the discharge surface of the ink jet head 102, a sheet pressure plate 109 is arranged.
Also, the ink jet recording apparatus is provided with a sheet feed roller 107 that carries a recording sheet 106 which serves as a recording medium to the recording area of the ink jet head 102, and also, with a sheet exhaust roller 108 which is arranged to exhaust the recording sheet 106 having a recorded object on it by the ink jet head 102. The sheet feed roller 107 and the sheet exhaust roller 108 are driven to rotate by use of a motor (not shown).
When the ink which is discharged from the ink jet head 102 adheres to the recording sheet 106 facing the discharge port surface of the ink jet head 102, the recorded images are formed on the surface of the recording sheet 106. Interlocked with recording to the recording sheet 106 by the ink jet head 102, the sheet feed roller 107 and the sheet exhaust roller 108 are rotated by the motor to exhaust the recording sheet 106 outside the ink jet recording apparatus in cooperation with the sheet pressure roller 109.
FIGS. 26A and 26B are views which illustrate the ink jet head cartridge to be mounted on the carriage 101 shown in FIG. 25. FIG. 26A is a perspective view which shows the ink jet head cartridge to be mounted on the carriage 101. FIG. 26B is a perspective view which shows the state where ink tanks are removed from the ink jet head cartridge shown in FIG. 26A.
As shown in FIG. 26A and FIG. 26B, the ink jet head cartridge 301 which is mounted on the carriage 101 comprises a tank holder 103 provided with the ink jet head 102; and ink tanks 111, 112, 113, and 114, which are detachably mountable on the tank holder 103. The ink tank 111 is for use of black ink; the ink tank 112 is for use of yellow ink; the ink tank 113 is for use of magenta ink; and the ink tank 114 is for use of cyan ink. Each of the ink tanks 111, 112, 113, and 114 is detachably mountable on the tank holder 103. Each of the ink tanks is exchangeable, which contributes to lowering the running costs of printing by the ink jet recording apparatus.
For each of the ink tanks 111, 112, 113, and 114, ink of the corresponding color is contained in it, respectively. Also, for each of them, the ink supply port is formed to supply the ink contained in it to the ink jet head 102. For example, the ink supply port 211 is formed for the ink tank 111. Then, black ink contained in the ink tank 111 is supplied to the ink jet head 102 through the ink supply port 211 in the state where the ink tank 111 is installed on the tank holder 103.
FIG. 27 is a cross-sectional view which shows the tank holder 103 and the ink jet head 102 represented in FIGS. 26A and 26B. As shown in FIG. 27, the upper surface of the box-type tank holder 103 is open, and the ink jet head 102 is arranged for one side portion on the bottom face of the tank holder 103. In the ink jet head 102, the silicon substrate 201 is supported by the base plate 205. On the silicon substrate 201, heaters or the like are formed as electrothermal converting means to generate thermal energy utilized for ink discharges.
Also, for the ink jet head 102, a joint 204 is provided to be connected with the ink supply port of the ink tank when the ink tank is installed on the hand holder 103. For the joint 204, an ink flow path 206 is formed to extend to the silicon substrate 201.
Now, exemplifying the ink tank 111 for use of black ink, the description will be made of the ink flow in an ink jet head cartridge of the kind. Ink in the ink tank 111 is supplied to the interior of the ink jet head 2 through the ink supply port 211 of the ink tank 111 and the joint 204. The ink which is supplied to the interior of the ink jet head 2 is supplied to the silicon substrate 201 through the ink flow path 206. Then, the ink thus supplied is discharged to a recording sheet which serves as the recording medium by the application of thermal energy generated by the heater on the silicon substrate 201.
FIGS. 28A to 28C are views which illustrate the ink tank 111 represented in FIGS. 26A and 26B. FIG. 28A is a perspective view which the ink tank 111, observed in the direction in which a second nail 132 is visible. FIG. 28B is a perspective view which shows the ink tank 111, observed in the direction in which a movable lever 130 is visible. FIG. 28C is a cross-sectional view which shows the ink tank 111.
As shown in FIGS. 28A and 28B, the ink tank 111 has the movable lever 130 having a first nail 131 for it on one side of thereof. On the other side of the ink tank 111, the second nail 132 is arranged. When the ink tank 111 is installed on the tank holder 103, the first nail 131 and the second nail 132 engage with a first hole 241 and a second hole 242 (see FIG. 27) formed on the tank holder 103, respectively. In this manner, the ink tank 111 is fixed to the tank holder 103. On the bottom face of the ink tank 111, the ink supply port 211 is arranged to be cylindrically extruded from the bottom face thereof.
Also, as shown in FIG. 28C, in the interior of the ink tank 111, an ink absorbent 136 is housed to retain ink by absorbing the liquid ink. In the interior of the ink supply port 221, the Joint member 137 is filled to be connected with the ink absorbent 136. When the ink tank 111 is installed on the tank holder 103, ink retained in the ink absorbent 136 is supplied to the ink jet head 102 from the ink supply port 211 through the joint member 137.
Now, in conjunction with FIGS. 29A to 29C, the description will be made of the procedures for the installation of the ink tank 111 onto the tank holder 103 of the ink jet head cartridge 301.
At first, as shown in FIG. 29A, the surface of the ink tank 111 on the ink supply port 211 side is placed to face the upper surface of the tank holder 103. And, the ink tank 111 is inserted into the interior of the tank holder 103 in the direction indicated by an arrow A, while the second nail 132 of the ink tank 111 is inclined downward.
Then, as shown in FIG. 29B, the second nail 132 of the ink tank 111 engages with the second hole 242 of the tank holder 103 at first when the ink tank is inserted along the side inclination of the holder 103 on the right side in FIG. 29B.
Further, as shown in FIG. 29C, when the ink tank 111 is pressed into the tank holder 103, the movable lever 130 is bent inward so as to enable the first nail 131 to engage with the first hole 241 of the tank holder 103. Thus, the ink tank 111 is fixed to the tank holder 103.
In this state, ink retained in the ink absorbent 136 is introduced to the ink jet head 202 through the joint member 137 of the ink supply port 211, and discharged from the discharge port (not shown) by the application of energy generated by the electrothermal converting means (not shown).
Here, in order to remove the ink tank 111, the movable lever 130 is bent inward to enable the first nail 131 to be drawn for the first hole 241 of the tank holder 103. Then, it becomes easy to remove the ink tank 111 from the tank holder 103.
In accordance with the conventional art described above, however, it is impossible for the user or the like who uses an ink jet recording apparatus for the first time to recognize the correct condition of the ink tank installation exactly when the ink tank is installed on the tank holder. As a result, in some cases, the installation is not completed as in the final condition which is represented in FIG. 29C.
Particularly, since the molding material becomes hardened under a low temperature environment, there is a need for exercising a large force to push in the ink tank onto the tank holder. As a result, there is a tendency that the ink tank is not pressed until it is installed perfectly. Then, if any recording is executed in the state where the ink tank is not installed on the tank holder perfectly, ink in the ink tank is not supplied to the ink jet head sufficiently to as to present a drawback that recording is not made exactly in some cases.
Also, it is possible to confirm the installation of the ink tank by means of a clicking sound (or by sensing it), but depending on the use environments, it becomes difficult to make such confirmation, and there is still a fear that the completion of the ink tank installation is not necessarily confirmed in such a manner in some cases.
Also, if the ink tank should be made smaller to meet the requirement of making the apparatus smaller, it is inevitable that the tongue portion of the movable lever of the ink tank should be made smaller accordingly. In this case, then, the user finds it difficult to remove the ink tank. Further, in a case where a plurality of ink tanks having ink of different colors should be arranged adjacent to each other in a tank holder, there is encountered a problem that it becomes inconvenient to handle ink tanks if the tongue portion of each movable lever of the ink tanks is made smaller as described above, because the user wrongly picks up the one next to the ink tank that he intends to remove at that time.
In consideration of the technical problems described above, the present invention is designed. It is an object of the invention to provide an ink tank with the excellent handling ease with which the use can recognize the correct installation of ink tank on the tank holder, an ink jet head cartridge, and an ink jet recording apparatus provided with the ink jet head cartridge.
Also, with the conventional structure described above, the breakage of the fulcrum portion of the foot section of the movable lever may take place if the user should unexpectedly drop the ink tank with the side where the movable lever is arranged downward or in some other accidental cases. As a result, the drawback that the ink tank cannot be installed on the tank holder may be encountered. Particularly, under the lower temperature environment, the mold material becomes hardened to be brittle, and there is a tendency that it becomes easier for the movable member to be broken in such accidental cases as described above.
Therefore, it is another object of the present invention to provide an ink tank with improved handling, which withstands the shock received when the ink tank is dropped or the unexpected shocks given from the outside, and also, to provide an ink jet head cartridge, as well as an ink jet recording apparatus provided with such ink jet head cartridge.
In order to achieve the objects described above, the ink tank of the present invention is detachably held by a tank holder having an arc shape portion of a specific curvature. This ink tank has also an arc shape portion of a specific curvature, and the arc center of the arc shape portion of the ink tank is in the same position as the arc center of the arc shape portion of the tank holder only when the ink tank is correctly installed on the tank holder.
This ink tank has the movable lever provided with the engagement nail to engage with the tank holder, and the movable lever is provided with the tongue portion on the upper portion of the engagement nail to be operated when the ink tank is removed from the tank holder, and the arc shape portion of the ink tank is the portion of the arc shape formed for the tongue portion.
The movable lever referred to in the preceding paragraph is resiliently connected with the ink tank, and a part of the connected portion is formed thinner in the thickness thereof.
Here, it is preferable that the arc shape portion of the ink tank is different in accordance with the ink capacity of the ink tank, and that the arc shape portion of the ink tank is different in accordance with the kind of ink in the ink tank.
The aforesaid movable lever is molded integrated with the ink tank.
The curvature radius of the ink tank and that of the tank holder are the same dimension.
Further, the ink head cartridge of the invention comprises a tank holder according to either one of those referred to in the preceding paragraphs, and an ink jet recording head for discharging ink to be supplied from the ink tank installed on the tank holder.
Further, the ink jet recording apparatus of the invention comprises a carriage which detachably holds an ink jet head cartridge described above, and which is supported to be able to reciprocate along the surface of a recording medium. Then, ink is discharged from the ink jet recording head portion of the ink jet head cartridge for recording on the recording medium in accordance with electric signals for ink discharges.
With the structure arranged as above, unless the ink tank is installed on the tank holder correctly, the arc center of the arc shape portion of the ink tank and that of the tank holder are not in the same position. Therefore, the connection between the arc shape portions of the ink tank and tank holder become unnatural at the time of installation. Thus, the user can recognize the incorrect installation of the ink tank by eye-sight so as to enable him to operate the installation again.
Also, in order to achieve the objectives discussed above, the ink tank of the present invention is detachably held by a tank holder which is provided with a movable lever having the engagement nail to engage with the tank holder, and resiliently supported on the foot section of the movable member. For this ink tank, a part of the foot section of the movable lever is formed thinner in the thickness thereof.
For the ink tank of the invention structured as described above, a part of the foot section of the movable lever is formed thinner in the thickness thereof. As a result, even if a shock destructive force is given to the movable lever to cause crack on the wall thickness portion, the development of such crack is blocked by the thinner thickness portion, hence preventing the movable lever from being broken.
The movable lever may be molded integrally, and the central portion of the movable lever may be made thinner in the thickness thereof. The thickness of the portion formed thinner may be less than a half the thickness of other portions of the food section of the movable lever.
Also, the movable lever is provided with the tongue portion that serves as the operational part when the ink tank is attached to or detached from the tank holder. It is preferable to provide an arc portion for this tongue portion. Particularly, in the state where the ink tank is installed, it is preferable to arrange the location where the tongue portion of the ink tank is positioned to be in the form of arc which is coaxial with the arc center of the tongue portion. This is desirable from the viewpoint of enhancing the reliability of installation.
Also, the ink jet head cartridge of the invention comprises a tank holder capable of detachably holding an ink tank referred to either one of the preceding paragraphs, and a liquid discharge head unit for discharging ink to be supplied from the ink tank.
Also, the in ink jet recording apparatus of the invention comprises a carriage which detachably holds an ink jet head cartridge referred to in the preceding paragraph, and according to claim 21, and which is supported to be able to reciprocate along the surface of a recording medium. Then, ink is discharged from the liquid discharge recording head unit of the ink jet head cartridge for recording on the recording medium in accordance with electric signals for ink discharges.
Further, the ink tank of the invention is detachably held on a tank holder having the arc shape portion of a specific curvature. For this ink tank, the movable lever is provided with the engagement nail to engage with the tank holder, and resiliently supported by the ink tank at the foot section thereof; the movable lever is provided with a tongue portion on the upper part of the engagement nail to be operated when attaching the ink tank to or detaching it from the tank holder; the tongue portion is provided with the arc shape portion of a specific curvature; and the arc center of the arc shape portion of the ink tank is in the same position of the arc center of the arc shape portion of the tank holder only in the position of the ink tank correctly installed on the tank holder, and at the same time, a part of the foot section of the movable lever is formed thinner in the thickness thereof.
It is preferable to make the arc portion of the ink tank different in accordance with the ink capacity of the ink tank.
Also, it is preferable to make the arc portion of the ink tank different in accordance with the kind of ink in the ink tank.
Also, it is preferable to make the thickness of the thinner portion less than a half the thickness of other portions of the foot section of the movable lever.
Other objectives and advantages besides those discuss above will be apparent to those skilled in the art from the description of a preferred embodiment of the invention which follows. In the description, reference is made to accompanying drawings, which form a part hereof, and which illustrate an example of the invention. Such example, however, is not exhaustive of the various embodiments of the invention, and therefore reference is made to the claims which follow the description for determining the scope of the invention.